1. Technical Field
The disclosure relates to a control device and a control method for an internal combustion engine.
2. Description of Related Art
Japanese Patent Application Publication No. 2007-32515 (JP 2007-32515 A) discloses a control device for an internal combustion engine that includes an intake variable valve timing (VVT) mechanism and an exhaust VVT mechanism.
In such an internal combustion engine, rotation phases of an intake camshaft and an exhaust camshaft with respect to a crankshaft are changed using the intake VVT mechanism and the exhaust VVT mechanism. Thus, valve timings of an intake valve and an exhaust valve are changed. In addition, in accordance with the operation state of the internal combustion engine, an overlap period of the intake valve and the exhaust valve is controlled. Thus, it is possible to achieve an improvement in the output of the internal combustion engine, an improvement in fuel efficiency, and a reduction in exhaust emission.
In the control device for the internal combustion engine of JP 2007-32515 A, when an operation is shifted from an acceleration operation to a steady operation, the valve timing of the exhaust valve is advanced by a predetermined amount and the valve timing of the intake valve is advanced by an amount larger than the predetermined amount from a state in which the overlap period of the exhaust valve and the intake valve is zero. According to this, the exhaust valve opens in a state in which an in-cylinder pressure is high, and hence it is possible to increase an internal exhaust gas recirculation (EGR) amount.